Interventional metabolic pathway inhibiting the apoptosis of hypertrophic cardiomyocytes induced by hypoxia-reperfusion——role of caspase-dependent and independent pathway / 中国药理学通报

ABSTRACT

Aim To illustrate the actions and molecular mechanisms of interventions taken to convert the metabolism pathways of cellular apoptosis caused by hypoxia and hypoxia-reperfusion in hypertrophic cardiomyocytes.Methods Angiotensin Ⅱ(0.1 ?mol?L-1)was applied to induce the hypertrophy of mice cardiomyocytes.The cardiomyocytes received the treatment of hypoxia-reperfusion in a tri-gas incubator to simulate the conditions of hypoxia-reperfusion.Before hypoxia/reperfusion,no drug intervention and pre-treatments of DCA(1 mmol?L-1),TMZ(5 ?mol?L-1),LC(50 ?mol?L-1)and AA(10 ?mol?L-1)were given respectively.The glucose and fatty acid oxidative metabolism rates were measured with radioactive counting methods.RT-PCR and Western blot methods were employed respectively to measure the mRNA and protein expression levels of cytochrome C and apoptosis inducers.The spectrophotometry method was used to measure the activity of Caspase-3 and Hoechst 33258 staining to quantify the percentage of cellular apoptosis.Results At post-hypoxia 12 h and post-reperfusion 4 h,the glucose oxidative metabolism rates in hypertrophic cardiomyocytes all decreased while the fatty acid oxidative metabolism rates increased.DCA,TMZ and LC all could inhibit both the reduction of glucose oxidative metabolism after hypoxia-reperfusion and the elevation of fatty acid oxidative metabolism after hypoxia-reperfusion.AA drove the reduction of glucose oxidative metabolism rate even lower and the fatty acid oxidative metabolism rate even higher in hypertrophic cardiomyocytes after ischemia/reperfusion.At the same time,DCA,TMZ and LC could inhibit the expression levels of mitochondrial cytochrome C and AIF mRNA and proteins,the nuclear translocation of cytochrome c and AIF proteins and the activity of caspase-3.And with the opposing actions to AA,DCA,TMZ and LC could inhibit the apoptotic rate of hypertrophic cardiomyocytes after hypoxia-reperfusion.And AA had the opposite effect.Conclusion Intervening in the metabolism pathway of hypertrophic cardiomyocytes was an effective way to prevent and control their programmed death through inhibiting the expression of mitochondrial apoptotic proteins.